It's been a while since I've worked on these, but it seems like there was a connector on the back door close to the fuel pump. You could plug the two wires together and that would bypass the engine safety shutdown system. Engine is protected by low coolant sensor and low oil pressure switch. Worth a try if wired that way? If that allows the engine to stay running, you will need to figure out which sensor or wiring is the problem and correct it? The early ones had the coolant sensor in the top radiator hose and any air in the cooling system would shut engine down. Remedy was to rotate the sensor to underside of hose. Later ones had the sensor in thermostat housing. Having said all that, I would have to agree that it is likely clogged line or crud in the fuel tank? Microbes grow in diesel and can form a sludge in the tank. The more ethanol the faster they grow and biodiesel is the worst?